USC running back Vavae Malepeai runs with the ball during the second half of a game against Stanford last September at the Coliseum. Quirks in the schedule and the fact both teams always play Notre Dame later in the season have pushed this rivalry to the first three weeks of the season often in recent years. (Photo by Sean M. Haffey/Getty Images)

LOS ANGELES — Rivalry games between college football teams usually kick off late in the season. The weather is colder. Leaves have turned color to the red of fall. Daylight hours wane.

In contrast, the latest edition of the USC-Stanford rivalry arrives much sooner on the calendar. For a fifth consecutive season, the Trojans and the Cardinal play in early September.

The scheduling quirk endures in the aftermath of the Pac-12’s expansion from earlier this decade. In the eight seasons of the expansion era, USC and Stanford have met six times in either Week 2 or Week 3, matchups that also serve as the teams’ conference openers.

Questions about the rivalry’s placement on the schedule are met with mixed feelings.

“I think we’d all prefer it be a little bit later, but I don’t mind it,” Stanford coach David Shaw said.

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“It is what it is,” USC coach Clay Helton said.

The most commonly cited factor for the early-season showdown is that both USC and Stanford annually play Notre Dame later in the season, usually in October and November, when all other Pac-12 schools exclusively play conference games.

As a result, the Trojans and the Cardinal are left with a bye during one of the first three weeks of the season. It is then filled by their matchup. Pac-12 teams only play three nonconference games to begin with, necessitating the early conference game.

When the conference expanded with the 2011 season, adding Colorado and Utah, it also shortened the regular season. The final weekend is now reserved for the Pac-12 championship game, eliminating other conference games, as had previously been set up. The athletic directors at USC and Stanford then agreed to stage their rivalry game during one of the first three weeks of the season to compensate for the shortened season and also preserve bye weeks for later in the fall.

Exceptions to the arrangement were made in 2011 and 2013 when USC and Stanford met in October and November due to previously scheduled nonconference games that conflicted in the first three weeks.

The most obvious result of the game’s occurrence in September is that it hands one of the conference’s traditional powers an early-season loss. The game is one of only two this Saturday that involve ranked teams. Most teams are still in the softer part of their schedules. Eight will play opponents from the Football Championship Subdivision (formerly Division I-AA), this weekend.

But it also functions as a barometer.

How good are the 17th-ranked Trojans after their season-opening win over UNLV? They will find out against the 10th-ranked Cardinal in Palo Alto.

“It’s fun,” said Cameron Smith, a senior linebacker for USC. “We get to see what kind of team we start out with at the beginning of the year.”

Sometimes, the results are not what they might like to see.

Smith recalled the 2015 season. Stanford had dropped its season opener at Northwestern, lowering expectations. But the Trojans lost to the Cardinal in Week 3, undone by a breakout game by running back Christian McCaffrey, who reached the 100-yard mark for the first time in his career.

The loss to the Cardinal in 2016, marking the Trojans’ worst start to a season in 15 years, also prompted a quarterback switch, with Helton swapping out Max Browne for Sam Darnold as the starter the following week.

Over the last five early September matchups, the Trojans are 2-3 against the Cardinal. They are 3-2 in games the following week, suffering tough road losses at Utah in 2016 and at Boston College in 2014 after facing Stanford.

“It’s got its ups and downs, playing them this early,” USC senior outside linebacker Porter Gustin said. “Maybe we haven’t gotten a rhythm, especially with a new quarterback, a new offense, a new challenge. At the same time, I think it’s going to be a good challenge for us. They’re figuring it out too. It’s their second game. So it’s not like they’ve been playing more games than us. It can certainly be more of a motivator for the rest of the season if it’s something positive.”

Last season, the Trojans blitzed the Cardinal 42-21, a victory that ultimately helped them capture the Pac-12’s South division and reach the conference championship game, where they defeated Stanford again.

Shaw said there had been some recent discussions about adding more conference games to the early-season schedule to allow for matchups beyond USC and Stanford. But nothing appears imminent due to other Pac-12 teams’ preexisting nonconference schedules in early September.

Lynn Swann, USC’s third-year athletic director, said last week the issue had not been discussed among the rest of the athletic department and added, “It’s not a huge topic.” Pac-12 athletic directors are tasked with approving the final schedules.

The rivalry game will be played at some point.

“It doesn’t matter,” Helton said. “When you’re USC, with our schedule, you’re going to either have nine Pac-12 conference games, Notre Dame, the likes of Texas, Alabama. It’s coming. They’re all good. If it’s game one, two or three, it’s your job to be prepared and be ready.”

Joey Kaufman is the USC beat writer for the Southern California News Group. Since joining the Orange County Register in 2015, he has also covered Major League Baseball and UCLA athletics. His work has been recognized by the Associated Press Sports Editors and Football Writers Association of America. Kaufman grew up in beautiful downtown Burbank.